diff options
Diffstat (limited to 'sysdeps/tile/tilepro/strlen.c')
-rw-r--r-- | sysdeps/tile/tilepro/strlen.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/sysdeps/tile/tilepro/strlen.c b/sysdeps/tile/tilepro/strlen.c new file mode 100644 index 0000000000..c40ee56c6f --- /dev/null +++ b/sysdeps/tile/tilepro/strlen.c @@ -0,0 +1,39 @@ +/* Copyright (C) 2011-2014 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library. If not, see + <http://www.gnu.org/licenses/>. */ + +#include <string.h> +#include <stdint.h> + +size_t +strlen (const char *s) +{ + /* Get an aligned pointer. */ + const uintptr_t s_int = (uintptr_t) s; + const uint32_t *p = (const uint32_t *) (s_int & -4); + + /* Read the first word, but force bytes before the string to be nonzero. + This expression works because we know shift counts are taken mod 32. */ + uint32_t v = *p | ((1 << (s_int << 3)) - 1); + + uint32_t bits; + while ((bits = __insn_seqb (v, 0)) == 0) + v = *++p; + + return ((const char *) p) + (__insn_ctz (bits) >> 3) - s; +} +libc_hidden_builtin_def (strlen) |